Shoulder Muscles Flashcards
deltoid origin
lateral one-third of the clavicle, acromion, the lower lip of the crest of the spine of the scapula
deltoid insertion
deltoid tuberosity of the humerus
deltoid action
abducts arm; medially & laterally rotate the arm
deltoid innervation
axillary nerve
deltoid artery
posterior circumflex humeral a.
Supraspinatus Origin
supraspinatous fossa
Supraspinatus Insertion
greater tubercle of the humerus (highest facet)
Supraspinatus Action
initiates abduction
Supraspinatus Inervation
suprascapular nerve
Supraspinatus Artery
suprascapular a.
Infraspinatus Origin
infraspinatous fossa
Infraspinatus Insertion
greater tubercle of the humerus (middle facet)
Infraspinatus Action
laterally rotates the arm
Infraspinatus Artery
suprascapular a.
Infraspinatus Innervation
suprascapular nerve.
Teres Minor Origin
upper 2/3 of the lateral border of the scapula
Teres Minor Insertion
greater tubercle of the humerus (lowest facet)
Teres Minor Action
laterally rotates the arm
Teres Minor Artery
circumflex scapular a.
Teres Minor Innervation
axillary nerve
Teres Major Origin
dorsal surface of the inferior angle of the scapula
Teres Major Insertion
crest of the lesser tubercle of the humerus
Teres Major Action
adducts the arm, medially rotates the arm, assists in arm extension
Teres Major Artery
circumflex scapular a.
Teres Major Innervation
subscapular nerve
Subscapularis Origin
medial two-thirds of the costal surface of the scapula (subscapular fossa)
Subscapularis Insertion
lesser tubercle of the humerus
Subscapularis Action
medially rotates the arm; assists extention of the arm
Subscapularis Artery
subscapular a.
Subscapularis Innervation
subscapular nerve
Quadrangle Space
Superior border: inferior border of Teres Minor
Inferior Border: Superior border of Teres Major
Medial Border: Lateral border of Long Head
Lateral Border: Medial border of lateral head
Axillary Nerves
Deltoid, Teres Minor
Collateral Circulation
Axillary artery cross the scapula towards humerus and descend inferiorly. If blockage in axillary occurs in scapular region, the subscapular artery can circumvent the blocked area around border of scapula.
